Some websites you may find useful:
Biermania - If the prospect of organising your own tour of German breweries seems too intimidating, have a look here. Andy runs regular trips to breweries in both Germany and the low countries.
Bierregion Franken - Online for more than a decade, Frank Wetzel's excellent website focuses solely on Franconia, providing details of all operational breweries together with many that have closed in recent years. Frank also has a holiday apartment in Bamberg which can be booked through the site.
The British Guild of Beer Writers - The who's who of the British beer writing world. If you want someone to write an article, conduct a tasting or just answer a beer-related question, this is the place to look.
European Beer Guide - Run by Ron Pattinson - once of Newark (Notts) but now resident in Amsterdam. As well as numerous pages on the German brewing and pub scene this excellent site has similar information on around a dozen other European countries.
Hausbrauereien und Bierdeckel - Regular contributor Alex Deuerlein's blog about his relentless search for new beermats, combined with detailed reports about new and future breweries.
The Online Beer Guide to Bamberg and Franconia - Although based in California, Fred Waltman regularly visits Franconia and has set-up this website for lovers of Franconian beers. All operating breweries in the region are included, many with visitor reports.
White Beer Travels - The late John White was well-known as an organiser of continental beer tours. His family have kept his comprehensive website online, and it includes a wealth of information on past visits, book reviews, etc. Although it leans towards Belgium, the German beer scene features prominently.
For other websites covering the German brewing scene, see page 518 of the Guide. If you'd like a link to your site, please feel free to contact me.